Fix running core.step when receiving an event while not waiting

When `time_to_wake` was <= 0, so when a coroutine needed to be executed 
as soon as possible, we didn't check for events, so we only performed a 
`core.step` with the blink timer.
This resulted in jerky reactions to input.

docs/api/system.lua

@@ -61,10 +61,10 @@ function system.poll_event() end
 ---
 ---Wait until an event is triggered.
 ---
----@param timeout number Amount of seconds, also supports fractions
----of a second, eg: 0.01
+---@param timeout? number Amount of seconds, also supports fractions
+---of a second, eg: 0.01. If not provided, waits forever.
 ---
----@return boolean status True on success or false if there was an error.
+---@return boolean status True on success or false if there was an error or if no event was received.
 function system.wait_event(timeout) end
 
 ---